/*
 * Copyright � 2002-2011 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.ComponentModel;
using System.Globalization;
using Spring.Core.TypeResolution;

namespace Spring.Core.TypeConversion;

/// <summary>
/// A custom <see cref="System.ComponentModel.TypeConverter"/> for
/// runtime type references.
/// </summary>
/// <remarks>
/// <p>
/// Currently only supports conversion to and from a
/// <see cref="System.String"/>.
/// </p>
/// </remarks>
/// <author>Rick Evans (.NET)</author>
public class RuntimeTypeConverter : TypeConverter
{
    /// <summary>
    /// Creates a new instance of the
    /// <see cref="Spring.Core.TypeConversion.RuntimeTypeConverter"/> class.
    /// </summary>
    public RuntimeTypeConverter() { }

    /// <summary>
    /// Returns whether this converter can convert an object of one
    /// <see cref="System.Type"/> to the <see cref="System.Type"/>
    /// of this converter.
    /// </summary>
    /// <remarks>
    /// <p>
    /// Currently only supports conversion from a
    /// <see cref="System.String"/> instance.
    /// </p>
    /// </remarks>
    /// <param name="context">
    /// A <see cref="System.ComponentModel.ITypeDescriptorContext"/>
    /// that provides a format context.
    /// </param>
    /// <param name="sourceType">
    /// A <see cref="System.Type"/> that represents the
    /// <see cref="System.Type"/> you want to convert from.
    /// </param>
    /// <returns>True if the conversion is possible.</returns>
    public override bool CanConvertFrom(
        ITypeDescriptorContext context,
        Type sourceType)
    {
        if (sourceType == typeof(string))
        {
            return true;
        }

        return base.CanConvertFrom(context, sourceType);
    }

    /// <summary>
    /// Returns whether this converter can convert the object to the specified
    /// <see cref="System.Type"/>.
    /// </summary>
    /// <param name="context">
    /// A <see cref="System.ComponentModel.ITypeDescriptorContext"/>
    /// that provides a format context.
    /// </param>
    /// <param name="destinationType">
    /// A <see cref="System.Type"/> that represents the
    /// <see cref="System.Type"/> you want to convert to.
    /// </param>
    /// <returns>True if the conversion is possible.</returns>
    public override bool CanConvertTo(
        ITypeDescriptorContext context, Type destinationType)
    {
        if (destinationType == typeof(Type))
        {
            return true;
        }

        return base.CanConvertTo(context, destinationType);
    }

    /// <summary>
    /// Converts the given value to the type of this converter.
    /// </summary>
    /// <param name="context">
    /// A <see cref="System.ComponentModel.ITypeDescriptorContext"/>
    /// that provides a format context.
    /// </param>
    /// <param name="culture">
    /// The <see cref="System.Globalization.CultureInfo"/> to use
    /// as the current culture.
    /// </param>
    /// <param name="value">
    /// The value that is to be converted.
    /// </param>
    /// <returns>
    /// An <see cref="System.Object"/> that represents the converted value.
    /// </returns>
    public override object ConvertFrom(
        ITypeDescriptorContext context,
        CultureInfo culture, object value)
    {
        if (value is string)
        {
            return TypeResolutionUtils.ResolveType(value as string);
        }

        return base.ConvertFrom(context, culture, value);
    }

    /// <summary>
    /// Converts the given value object to the specified type,
    /// using the specified context and culture information.
    /// </summary>
    /// <param name="context">
    /// A <see cref="System.ComponentModel.ITypeDescriptorContext"/>
    /// that provides a format context.
    /// </param>
    /// <param name="culture">
    /// The <see cref="System.Globalization.CultureInfo"/> to use
    /// as the current culture.
    /// </param>
    /// <param name="value">
    /// The value that is to be converted.
    /// </param>
    /// <param name="destinationType">
    /// The <see cref="System.Type"/> to convert the
    /// <paramref name="value"/> parameter to.
    /// </param>
    /// <returns>
    /// An <see cref="System.Object"/> that represents the converted value.
    /// </returns>
    public override object ConvertTo(
        ITypeDescriptorContext context,
        CultureInfo culture, object value, Type destinationType)
    {
        if (value is Type
            && destinationType == typeof(string))
        {
            return ((Type) value).AssemblyQualifiedName;
        }

        return base.ConvertTo(context, culture, value, destinationType);
    }
}
